The turbo I'm using is a Hitachi HT18.
The reason I chose the HT18 is it tops out efficiency at 0.9bar of which I will only need max 0.8bar to hit my 130kW goal, and it was cheap
Basically the UD40 trucks use the TD42ti motors, so the manifold and turbo fit the TD42 perfectly.
The turbo I sourced from a fellow Patroller for R3000.
It came off of a running Patrol that replaced the turbo for more horses.
The manifold I hunted like a mad man all over the country until I found it at a truck breaking yard in JHB for R2000.
Thanks to Tinus for going to check it out and picking it up for me
I had planned on doing a rebuild on the turbo simply because I don't plan on pulling it at a later stage to do the same thing, so while it's off just do it anyway.
Turned out to be a wise decision as I found the oil seals were poked, but not enough to notice on the running vehicle.
To send the turbo in to rebuild and balance would have been around R4500, so once again I did it myself
I sourced a rebuild kit from Turbos Online in CT for R550.
I had to 're purpose' an old pair of needle nose pliers into cir clip pliers to get down into the turbo core and remove the 4 retainer clips of the journal bearings.
I Googled and Youtubed rebuilding turbos until it became a disorder
It's actually a really easy job
Steps are as follows :
- Remove clamp bolts on compressor and impeller housings.
- With a scribe or sharp implement score an alignment line on the core and housings to keep the orientation to put back on the vehicle.
- A slight tapping with a rubber mallet will pop the housings loose.
- Clamp the impeller nut (exhaust side) into a vice as it is welded to the impeller and shaft.
- Remove the nut from the shaft on the compressor wheel side.
- With a scribe or sharp implement score an alignment line on top of the compressor wheel and on the shaft to make sure you will be able to line them up on reassembly to keep the balancing correct.
- Remove the compressor wheel carefully ! The veins are very brittle.
- Lightly tap the reverse side of the backing plate with a rubber mallet to pop it off of the core.
- Clamp the core in the vice and lightly encourage the shaft out with a rubber mallet. The whole shaft & impeller wheel will drop through the core.
- Remove journal bearings from the core and replace, along with all the other seals.
- The critical seals are the compressor seal on the backing plate and the piston oil seal on the shaft at the impeller wheel.
- To replace the piston oil seal, spread the gap gently with the correct tool (not a pliers or screwdriver
) and drop down onto the groove.
- The open gap of the piston oil seal MUST be on top directly inline with the turbo oil feed. If it's not, it will leak and the turbo will smoke.
- The shaft and impeller wheel assembly will click into place (remember the piston oil seal gap alignment).
- Reassemble the backing plate and compressor wheel and line up the marks you made for balancing.
- Assemble clamps and bolts on the housings.
Easy peezy !
I found out the hard way that I had the wrong rebuild kit for my HT18
They had sent me a 2nd generation HT18 kit and mine ( Murphy's law) was a 1st generation turbo.
The only difference was mine had a carbon seal on the backing plate and the 2nd gen has a dynamic seal.
The carbon seal is a very scarce item to find, but Donovan from Turbos Online sourced it chop, chop and it was in my hands in no time with no charge.
I had to machine my own tool to seat the carbon seal into the backing plate, because the carbon seal is very brittle and you have to apply pressure on the steel casing.
So off to the lathe and I machined a custom tool that would fit in my drill press chuck.
I used the drill press as an arbor press to keep the force evenly distributed on the casing.
I took the core to The Turbo Shop and they balanced and tuned the core for R370.
They said the core was perfect and only a tiny tune up was required to get the max efficiency out of it
So... from R4500 having it done by a company, I rebuilt it myself for R920.
R3580 saved
Turbo - R3000
Manifold - R2000
Turbo rebuild - R920
Total - 5920